Load-balancing groups without any buckets for remote MIPs

Sporadic issue wherein when MIPs are learnt, perform delete and add Transport
zone (ITM). The corresponding groups referred in table-21 flows for
remote MIPs have Select Groups without any buckets in one of the DPN.

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cookie=0x8000003, duration=478.949s, table=21, n_packets=0, n_bytes=0, priority=42,ip,metadata=0x30d52/0xfffffe,nw_dst=20.0.0.150 actions=group:150014

cookie=0x8000003, duration=518.746s, table=21, n_packets=81, n_bytes=9558, priority=138,ipv6,metadata=0x30d52/0xfffffe,ipv6_dst=2001:db8:0:2::666 actions=group:150018

group_id=150014,type=select
group_id=150018,type=select

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